Traditional compressors include swash plate compressors. Usually, a swash plate type compressor includes a drive shaft, a swash plate connected together with the drive shaft, and several pistons operatively connected with the swash plate. When a drive unit drives the drive shaft to rotate in a well-known manner, the swash plate will bring each piston within cylinders into reciprocating motion.
For example, U.S. Pat. No. 5,009,574 discloses a traditional swash plate compressor, in the structure of which a swash plate is fixedly integrated on a drive shaft, such that the swash plate rotates together with the drive shaft. In other words, the swash plate does not rotate relative to the drive shaft. During the operation of a traditional swash plate compressor, the piston simply performs reciprocating motion. In such a structure, it further includes a sliding shoe, through which the swash plate drives the piston into reciprocating motion. Since the swash plate rotates together with the drive shaft, it causes high speed sliding motion between each sliding shoe and the swash plate.
The characteristic high speed sliding motion between the sliding shoe and the swash plate within the swash plate compressor may result in high friction loss and low loading capacity, and particularly, the circumstances become more serious in large volume compressors. Thus, as an improvement to swash plate compressors, wobble plate compressors in the prior art disengage the motion of the swash plate from the drive shaft, trying to reduce the above described friction loss.
For example, U.S. Pat. No. 2,335,415 discloses a wobble plate compressor structure, and in this structure, a wobble plate is connected to a hub of a drive shaft via an anti-friction bearing, such that the wobble plate performs wobbling motion without rotating together with the drive shaft; in other words, there is only slight sliding motion between the wobble plate and the sliding shoe, and sliding friction with high speed motion between the traditional swash plate and the sliding shoe has been replaced by rolling friction of the bearing. However, the structure reduces friction loss, but it is not compact enough, and lacks industrial applicability.
U.S. Pat. No. 5,239,913 discloses another typical wobble plate compressor structure. In this structure, a force from a top of the piston is directed to a bearing via a connecting rod and the wobble plate; for compressors using a single-way piston, such a wobble plate structure is conventionally usable, however, for larger volume compressors requiring a two-way piston, this structure is obviously not suitable, because there is totally no sufficient space for mounting the bearing and the connecting rod at a same position.
In addition, in this and similar structures, the wobble plate is connected with each piston via a piston rod. Thus, in this piece of prior art, it essentially requires a wobble plate stopper to stop the wobble plate from rotating, which makes the compressor structure complicated, resulting in a uneven or unbalanced, complicated manner of rotation, which in turn produces vibrations and noises.
Thus, a novel wobble plate compressor structure is needed, which may, at the same time of maintaining its applicable range, reduce friction loss, improve energy conversion efficiency, and meanwhile overcome the above described problems of existing wobble plate structures.